Derating DC

[Horton]

Do the same derating values apply for direct current when installing multiple conductors in a conduit?

 

[charlie b]

Yes. The ampacity of a wire has to do with the impact of the heat generated by current on the insulation system. DC current also creates heat.

 

[Horton]

RE

RE

Thanks for the clarification.

 

[dbuckley]

Just going a step further - when a current value is used for an AC circuit, it is a RMS current value. The RMS value of an AC current is defined as having the same heating effect as the same DC current.

So for this reason the AC and DC current ratings are interchangable.